The North Dakota Geological Survey said it detected shallow natural gas in 52 of the state's 53 counties. It's a prospect that eventually could lead to energy development well beyond the booming oil- and coal-producing regions in western North Dakota, said Ed Murphy, the state geologist and director of the Geological Survey.

The agency released its findings this month after a five-year, $65,000 study.

"The benefits of this study may not be seen for years, but at some point somebody is going to be looking at that natural gas," Murphy said.

Shallow gas is found at depths of 5,000 feet or less and much of what has been discovered in North Dakota is just 200 feet underground, said Fred Anderson, a geologist with the state Geological Survey in Bismarck.

Natural gas in North Dakota is normally found at depths of more than 10,000 feet and is processed as a byproduct of oil production from horizontal drilling and hydraulic fracturing, which uses pressurized fluid and sand to break open oil-bearing rock.

"It's great to assess these resources all across North Dakota," said Ron Ness, president of the North Dakota Petroleum Council. But just as important, he said, the study refutes an argument by environmentalists that hydraulic fracturing harms water wells and aquifers.

"It's mythical (that hydraulic fracturing, also known as fracking) puts gas in the water supply," said Ness, whose group represents about 160 companies working in the state's oil patch. "The reality is natural gas is omnipresent in North Dakota."

Not everyone agreed.

"The study doesn't shed much light on the impacts of fracking," said Wayde Schafer, a North Dakota spokesman for the Sierra Club. "There are a number of chemicals in fracking that could be migrating into drinking water wells. But first, the industry has to tell us what chemicals they are using so we know what to test for."

North Dakota natural gas production was pegged at a record 10.6 million cubic feet in November, the most recent figures available. The record November production from the rich Bakken and Three Forks formations, extended a record monthly production streak that began a year ago.

About 20 percent of natural gas from the state's booming oil patch is being burned off and wasted at present because of the lack of collecting systems and pipelines needed to move it to market.

"The challenge has been keeping up with what we have now," said Justin Kringstad, director of the North Dakota Pipeline Authority.

More than $1 billion in pipeline projects are either planned or under way in western North Dakota to move oil and natural gas. Industry officials say adding infrastructure to capture shallow natural gas is unlikely anytime soon.

Depressed prices also are a challenge, with a glut of natural gas on the market at present, Kringstad said. Natural gas is fetching less than a third of the price it was in 2008, he said.

In North Dakota, shallow gas currently is being tapped at only a few wells in Bowman County, in the southwestern part of the state, said Anderson, a geologist.

Geologists are uncertain of the source of shallow natural gas in North Dakota, whether it comes from shallow shales and sediments or if it is migrating from deeper reservoirs, Murphy said. The agency will ask North Dakota lawmakers for additional funding this year to study the source, he said.

Geologists have suspected for more than a century that North Dakota holds shallow gas deposits based on reports of gas emanating from water wells.

The Geological Survey began collecting anecdotes in 2006 from North Dakotans who claimed water from their faucets could be set afire. Dozens of incidents were recorded and helped researchers pinpoint potential deposits.

"There were some real colorful stories," Anderson said. "Like a guy sitting on the can and lighting a match and boom! That kind of thing."

State geologists and graduate students from North Dakota State University, the University of North Dakota, Dickinson State University and Minot State University tested 4,325 water monitoring wells across the state and found natural gas in 905 of them, or about 21 percent.

Anderson said shallow natural gas testing occurred in every county except Sioux County, which is largely federal land and incorporates the Standing Rock Indian Reservation. It's likely shallow natural gas occurs in that county too, he said.